<?php
/**
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cloud
 * @subpackage DocumentService
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/*
 * @see Zend_Cloud_DocumentService_QueryAdapter
 */
require_once 'Zend/Cloud/DocumentService/QueryAdapter.php';

/**
 * Class implementing Query adapter for working with Azure queries in a
 * structured way
 *
 * @todo       Look into preventing a query injection attack.
 * @category   Zend
 * @package    Zend_Cloud
 * @subpackage DocumentService
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query implements Zend_Cloud_DocumentService_QueryAdapter {
	/**
	 * Azure concrete query
	 *
	 * @var Zend_Service_WindowsAzure_Storage_TableEntityQuery
	 */
	protected $_azureSelect;
	
	/**
	 * Constructor
	 *
	 * @param  null|Zend_Service_WindowsAzure_Storage_TableEntityQuery $select Table select object
	 * @return void
	 */
	public function __construct($select = null) {
		if (! $select instanceof Zend_Service_WindowsAzure_Storage_TableEntityQuery) {
			require_once 'Zend/Service/WindowsAzure/Storage/TableEntityQuery.php';
			$select = new Zend_Service_WindowsAzure_Storage_TableEntityQuery ();
		}
		$this->_azureSelect = $select;
	}
	
	/**
	 * SELECT clause (fields to be selected)
	 *
	 * Does nothing for Azure.
	 *
	 * @param  string $select
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 */
	public function select($select) {
		return $this;
	}
	
	/**
	 * FROM clause (table name)
	 *
	 * @param string $from
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 */
	public function from($from) {
		$this->_azureSelect->from ( $from );
		return $this;
	}
	
	/**
	 * WHERE clause (conditions to be used)
	 *
	 * @param string $where
	 * @param mixed $value Value or array of values to be inserted instead of ?
	 * @param string $op Operation to use to join where clauses (AND/OR)
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 */
	public function where($where, $value = null, $op = 'and') {
		if (! empty ( $value ) && ! is_array ( $value )) {
			// fix buglet in Azure - numeric values are quoted unless passed as an array
			$value = array ($value );
		}
		$this->_azureSelect->where ( $where, $value, $op );
		return $this;
	}
	
	/**
	 * WHERE clause for item ID
	 *
	 * This one should be used when fetching specific rows since some adapters
	 * have special syntax for primary keys
	 *
	 * @param  array $value Row ID for the document (PartitionKey, RowKey)
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 */
	public function whereId($value) {
		if (! is_array ( $value )) {
			require_once 'Zend/Cloud/DocumentService/Exception.php';
			throw new Zend_Cloud_DocumentService_Exception ( 'Invalid document key' );
		}
		$this->_azureSelect->wherePartitionKey ( $value [0] )->whereRowKey ( $value [1] );
		return $this;
	}
	
	/**
	 * LIMIT clause (how many rows to return)
	 *
	 * @param  int $limit
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 */
	public function limit($limit) {
		$this->_azureSelect->top ( $limit );
		return $this;
	}
	
	/**
	 * ORDER BY clause (sorting)
	 *
	 * @todo   Azure service doesn't seem to support this yet; emulate?
	 * @param  string $sort Column to sort by
	 * @param  string $direction Direction - asc/desc
	 * @return Zend_Cloud_DocumentService_Adapter_WindowsAzure_Query
	 * @throws Zend_Cloud_OperationNotAvailableException
	 */
	public function order($sort, $direction = 'asc') {
		require_once 'Zend/Cloud/OperationNotAvailableException.php';
		throw new Zend_Cloud_OperationNotAvailableException ( 'No support for sorting for Azure yet' );
	}
	
	/**
	 * Get Azure select query
	 *
	 * @return Zend_Service_WindowsAzure_Storage_TableEntityQuery
	 */
	public function getAzureSelect() {
		return $this->_azureSelect;
	}
	
	/**
	 * Assemble query
	 *
	 * Simply return the WindowsAzure table entity query object
	 *
	 * @return Zend_Service_WindowsAzure_Storage_TableEntityQuery
	 */
	public function assemble() {
		return $this->getAzureSelect ();
	}
}
